The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 11, 1997
Filed:
Jun. 05, 1995
Applicant:
Inventor:
Charles B Mattas, Glenview, IL (US);
Assignee:
North American Philips Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315244 ; 315224 ; 315D / ;
Abstract
A lamp driving circuit having a series inductor and capacitor (L-C) in which the lamp load is connected in parallel with the capacitor. During pre-ignition of the lamp load, the driving signal supplied by a half-bridge oscillator includes a fundamental frequency and higher odd harmonics including a third harmonic of the fundamental frequency. The resonant frequency of the series connected L-C circuit is at least .sqroot.5 times greater than the fundamental frequency but not equal to the higher odd harmonic frequencies, preferably less than the third harmonic of the driving signal.